Distribution Pattern and Physical Mapping of CCC Plasmid-Mediated Multidrug-Resistance in some G-ve Bacteria Recovered from Hospitals and Haemodialysis Units Wastewater at Al-Madinah Al-Munawarah

ObjectiveInvestigation of the presence and distribution pattern of plasmid-linked antibiotic resistance amongst Gram-negative bacterial strains recovered from wastewater of hospitals and haemodialysis units. Drawing up a physical map of the most frequently distributed plasmidsMethodsRepresentatives G-ve bacterial strains; 59 isolates, were chosen from a previous study for the same authors, as of the most resistant ones (resist more than 3 up to 9 antibiotics to  > 100 μg/ml.). Miniprep protocol and gel electrophoresis technique were adopted for the detection and isolation of ccc plasmid DNA from the differentially-isolated G-ve bacteria. Restriction analysis using 11 DNA restriction enzymes and “Plasp” computer program against λ phage DNA digested with Hind III, for physical mapping of the most distributed plasmid.ResultsResults revealed the presence of seven different plasmids, distributed as 1-3 different types of plasmids in 68% (40/59) of the strains; chosen as representatives of the most resistant ones (resist more than 3 up to 9 antibiotics to > 100 μg/ml.). The detected plasmid sizes were estimated against HindIII-digested λ phage and found ranged from 36,844 to 2,027 bp. Preliminary physical mapping was constructed for the plasmid (23130 bp) that was the most distributed amongst more than 90% of the plasmid-bearing strains and was the only found singly.ConclusionThe isolated, characterized and the mapped plasmid (s), suggest the possibility of high rate of both vertical and horizontal distribution of these plasmids amongst the isolated G-ve bacterial Genera and species.